The present invention relates to pourable sulfone percarboxylic acid bleach detergent compositions which are chemically stable.
The ability of certain materials to bleach is widely used to remove discolorations or stains from fabrics. Although the exact mechanism by which bleaching agents function is only partially understood, it is generally known that many stains and soils possess a series of alternating single and double bonds and that loss of color can occur if one of the double bonds is destroyed. Thus, a material which can eliminate a double bond may be an effective bleach.
Categories of bleaches which are well known in the art include chlorine releasing compounds, inorganic oxygen bleaches and organic oxygen bleaches. Chlorine releasing compounds have certain disadvantages associated with their use such as, for example, their tendency to weaken or degrade fabrics, a tendency to react with other components of compositions in which they are present and their tendency to fade the colors of many dyed fabrics. Also, some bleaching conditions cause yellowing of certain synthetic or resin treated fabrics.
While inorganic oxygen bleaches overcome many of the disadvantages found with active chlorine releasing compounds, they have the disadvantage that they must be used at relatively high temperatures such as 85.degree. C. or higher.. This drawback becomes significant in light of the modern trend of using lower wash temperatures which are generally less than about 60.degree. C. in order to reduce energy cost and prolong the life of the fabric. As a result, it is generally necessary to improve the low temperature performances of inorganic oxygen bleaches through the addition of agents known as bleach activators. Unfortunately, this approach typically requires the use of either a large excess of the inorganic oxygen bleach or the use of a bleach activator in order to obtain an acceptably complete and rapid release of the active bleach species. Still another disadvantage is that the bleach activator must contain within its structure moieties which, upon release of the effective bleaching species, become side products contributing little or nothing to the bleach activity. Thus, the inclusion of these moieties tends to be wasteful.
The disadvantages of chlorine bleaches and inorganic oxygen bleaches, whether used alone in or combination with activators, can be overcome by the use of effective organic oxygen bleaches, especially the peroxycarboxylic acids. Unfortunately, when dissolved in water, percarboxylic acid bleaches are unstable, losing their active oxygen and converting to carboxylic acid. Thus, it is not possible to make a stable aqueous bleach solution with most percarboxylic acids. However, a pourable bleach can be made with percarboxylic acids of low water solubility by dispersing the peracid in water with stabilizing agents to maintain the percarboxylic in suspension or slurry. The presence of water in these bleach compositions accelerates their decomposition on storage such that it is difficult to obtain acceptable shelf life. Thus, there is a continuing need for chemically stable aqueous slurry peroxycarboxylic acids for use in effective bleaching of fabrics.